1. Field of the Invention
The present invention relates to a water-based hologram paper, and more particularly to a water-based hologram paper that is environmentally friendly and highly recyclable and has anti-counterfeiting capability for products, and low contamination and low cost in manufacture.
2. Description of Related Art
Conventional paper substances applied for goods containers or packing material are printed with patterns on an outside periphery to increase appearance attraction to the goods. In order to identify manufacturers or trademarks, laser molding technology is applied to attach laser membranes on the paper substances to achieve laser hologram papers for distinguishability from counterfeits. The conventional laser membranes are usually made of polyvinyl chloride (PVC) and polyethylene glycol terephthalate (PET) plastic membranes that are compressed to combine with the paper substrate. Because of adding the plastic membranes, the manufacturing costs of the laser hologram papers are correspondingly increased. Moreover, laser grains on the plastic membranes are easily mis-aligned with printed patterns on the paper substrates when the plastic membranes are processed in forming the laser grains in partial sections, locating the patterns at desired positions and even other processes after printing. Therefore, the resulting mismatch of grains and patterns causes the quality of the laser hologram papers to decrease. Additionally, the laser hologram papers are barely recyclable because separating the plastic membrane and the paper substrate is difficult and complex and has high operational cost.
By covering them with the plastic membranes, the laser hologram papers in the form of anti-counterfeiting labels can be completely detached from the goods. Therefore, offenders usually peel the laser hologram papers off and attach them on fake goods to pass them off as genuine ones.
With regard to manufacturing methods for the laser hologram papers, four conventional methods according to different types of laser hologram papers are described as the following:
1. Transparent laser hologram papers entirely with laser grains: the PET plastic membranes are treated with a corona treatment and then a solvent-based resin serving as a bridging agent is coated on surface of the PET plastic membrane after the corona treatment, wherein, the resin is composed of 35±2 wt % acrylate resin, 50±2 wt % isopropanol and 35±2 wt % water. The coated PET plastic membranes are subjected to compression molding and then combined to a paper substrate with printed patterns to achieve the laser hologram papers.
However, the PET plastic membranes on the laser hologram papers can not be recycled and are mostly discarded so that the PET plastic material is wasted and manufacturing cost is high.
2. Transparent laser hologram papers having laser grains in partial sections: the plastic membranes are thermally ironed by means of a gilding operation to attach on partial sections of the paper substrates to complete the patterns.
However, the gilding operation is expensive in operational cost and the patterns are easily mis-aligned so that quality of the laser hologram papers is low.
3. Aluminum-coating laser hologram papers entirely with laser grains: the PET plastic membranes are treated with the corona treatment and the solvent-based resin serving as a bridging agent is coated on the PET plastic membranes. Then, the coated PET plastic membranes are subjected to compression molding to process a working face and are further coated with an aluminum film on the working face by means of vapor deposition. After forming the aluminum film, two faces of the PET plastic membranes are coated again with the solvent-based resin and then combined with a paper substrate to carry out the printing to achieve the laser hologram papers.
In this method, partial laser grains and the patterns are covered by print ink which results in the laser hologram papers having poor quality in appearance.
4. Aluminum-coating laser hologram papers having laser grains in partial sections: the PET plastic membranes are treated with the corona treatment and then the solvent-based resin serving as a bridging agent is coated on the surface of the PET plastic membrane after the corona treatment. The coated PET plastic membranes are subjected to compression molding with a laser nickel board to form the laser grains in partial sections at a working face. Then, the working face is coated with an aluminum film by means of vapor deposition. Lastly, the treated PET plastic membranes are coated with the solvent-based resin at their two sides and then combined with a paper substrate to carry out the printing to achieve the laser hologram papers.
However, laser grains on the plastic membrane and printed patterns on the paper substrate can not be precisely aligned with each other whereby the quality of the laser hologram papers is poor.
The present invention has arisen to mitigate or obviate the disadvantages of the conventional laser hologram papers and the conventional methods for manufacturing the laser hologram papers.